Preliminary Design of Improvement of Output Power and Bandwidth for Terahertz EIK

This paper presents a preliminary study and numerical calculations for a high-power, high-efficiency, wide-bandwidth extended interaction klystron (EIK) based on mode overlap and multiple resonant cavities in the terahertz frequency band. The 11-gap intracavity mode with a center frequency of 0.22 THz is analyzed for its high frequency characteristics and electric field distribution. The adjacent operating modes of the
$\pi$
-mode,
$\pi+1$
-mode, and
$\pi+2$
-mode of the TM11 mode are selected to achieve mode overlap and expand the bandwidth. The number of cavity gaps and the length ratios of long and short slots are optimized to achieve proper frequency spacing between modes. The S-parameter analysis of the extracted structure input window cold measurement results obtained a −5 dB bandwidth greater than 2.5 GHz.